The Minnesota Department of Health said the investigation into an outbreak of illnesses at a campground in Zumbrota is ongoing as officials work with the campground owner determine ongoing risks and take steps to limit them.

A release said MDH has now identified 72 people who have experienced symptoms from waterborne illness outbreak associated with the Shades of Sherwood Campground.

According to the release, the owner temporarily closed the swimming pool and hyper-chlorinated it to kill any Cryptosporidium, which along with Shiga toxin-producing E. coli is believed to have caused the illnesses. The pool has since reopened.

Signs have also been posted around the pool warning visitors not to swim for two weeks if they have been ill with diarrhea. A man-made water pond at the campground has also been closed to swimming. The release said the pond is constructed in such a way that it cannot be effectively treated to remove Cryptosporidium and other pathogens.

The release said the 72 people identified have symptoms consistent with cryptosporidiosis or STEC infection, including diarrhea or vomiting for at least three days. The first case became ill on July 1, the most recent on Aug. 3.